title: Determination of organophosphorus pesticides and metabolites in cereal-based baby foods and wheat flour by means of ultrasound-assisted extraction and hollow-fiber liquid-phase microextraction prior to gas chromatography with nitrogen phosphorus detection.
abstract: A new method based on hollow-fiber liquid-phase microextraction (HF-LPME) has been developed for the determination of a group of organophosphorus pesticides, including some of their metabolites, in two commercial cereal-based baby foods and one wheat flour prior to gas chromatography-nitrogen phosphorus detection. Samples were first extracted by ultrasound-assisted extraction with acetonitrile (ACN) containing 1.25% (v/v) of formic acid. After evaporation and reconstitution in Milli-Q water, the HF-LPME procedure, using 1-octanol as extraction solvent, was applied followed by a desorption step in ACN, which clearly improved the performance of the technique. The effects of sample pH, ionic strength, stirring rate, extraction temperature and time as well as the desorption procedure were investigated. Under the optimum conditions that involved the extraction of the analytes from 10 mL of the water reconstituted extract at pH 7.0 containing 5% (w/v) of NaCl for 45 min at 960 rpm, the method was validated in terms of linearity, precision and accuracy. The limits of detection (LODs) were between 0.29 and 3.20 μg/kg. The extraction of Milli-Q water, as an example of the applicability of the procedure to aqueous samples, allowed achieving LODs in the range 0.01-0.04 μg/L. Such values, together with the ones achieved for the rest of the samples, are below or equal to the maximum residue limits specified by the European Union.
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Universidad de La Laguna (ULL), Avenida Astrofísico Francisco Sánchez, s/n° 38206 La Laguna, Tenerife, Spain.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: González-Curbelo
authors.forename: Javier
authors.initials: J
authors.lastname: Hernández-Borges
authors.forename: Teresa María
authors.initials: TM
authors.lastname: Borges-Miquel
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Rodríguez-Delgado
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D002523:Edible Grain / Q000737:chemistry; D005433:Flour / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D007225:Infant Food / Q000032:analysis*; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000379:methods*; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D009994:Osmolar Concentration; D010573:Pesticide Residues / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D015203:Reproducibility of Results; D012965:Sodium Chloride / Q000737:chemistry; D013010:Sonication; D014908:Triticum / Q000737:chemistry
chemical_list: D009943:Organophosphorus Compounds; D010573:Pesticide Residues; D012965:Sodium Chloride
keywords: Cereal-based baby foods; Gas chromatography-nitrogen phosphorus detection; Hollow-fiber liquid-phase microextraction; Organophosphorus pesticides; Ultrasound-assisted extraction; Wheat flour